Enbridge shuts down oil flow through Straits of Mackinac pipeline due to high winds, waves

A diver working on behalf of the nonprofit National Wildlife Federation inspects the Line 5 oil pipelines at the lake bottom in the Straits of Mackinac during a July 2013 dive.
(Photo: Courtesy of National Wildlife Federation)

DETROIT - High winds and waves on Tuesday prompted Enbridge Energy to temporarily suspend operation of its Line 5 underwater oil pipelines in the Straits of Mackinac, the Michigan Agency for Energy announced.

It's the first activation of components in a new agreement between the state and Enbridge designed to increase safety and transparency related to the twin, 64-year-old pipelines, which ship more than 23 million gallons of crude oil and natural gas liquids through the Straits daily.

Wave heights reached more than 9 feet in the Straits Tuesday, according to the NOAA Great Lakes Coastal Forecasting System (GLCFS) Nowcast model. The agreement between the State and Enbridge Energy Partners calls for the discontinuation of Line 5 operations in the Straits during sustained adverse weather conditions where wave heights reach more than 8 feet.

Enbridge spokesman Ryan Duffy said Line 5 was shut down in the Straits at 11:37 a.m. Tuesday.

"The situation is being monitored and the line will be restarted when conditions improve," he said.

Valerie Brader, executive director for the Michigan Agency for Energy, in a statement praised the quick action to adhere to the agreement.

"The purpose of the State’s agreement with Enbridge was to find practical solutions to concerns we had about the operation of Line 5 and the safety of the Great Lakes,” she said. “Enbridge’s action today shows the steps outlined in the plan will have immediate and long-term positive outcomes.”

Critics of Line 5's continued operation in the Straits contend that a pipeline rupture and oil spill there would devastate the Great Lakes ecology, island and shoreline communities, and the state economy.

After months of state frustration with Enbridge's lack of forthrightness about issues with the underwater oil pipelines' loss of protective coating and missing, required anchor supports, state and Enbridge officials on Nov. 27 announced a new agreement. It calls on the Canadian oil transportation giant to, among other things, put the portion of Line 5 that travels under the St. Clair River into Sarnia, Ontario, into a new pipe in a tunnel under the river bed, and to study possibly creating a tunnel under the lakes for Line 5 in the Straits of Mackinac. The two sides agreed to have a plan for how to proceed with the Straits pipelines by next Aug. 15, or the state may pursue other roads, including calling for the shutdown of the pipes altogether, Brader said as the pact was announced.

The Michigan Agency for Energy on Tuesday also announced the two state representatives that will "monitor Enbridge’s actions, review and verify the company’s data, and participate fully in each of the evaluations required under the agreement."

Michael A. Mooney is the chair professor of underground construction and tunneling at Colorado School of Mines. He is the founding director of the university’s Center for Underground Construction and Tunneling, and is a licensed professional engineer.

Daniel Cooper is president of HT Engineering, Inc. of Grand Rapids and is a licensed professional engineer in Michigan, New Jersey, and Ohio. He has worked since 1981 in the design and management of natural gas and liquid petroleum production, processing, transportation, and distribution projects.

“Both of these men are the ideal engineers for the tasks at hand,” Brader said. “In Dan Cooper, we have a Michigander who knows exactly what’s at stake for his state’s environment. Mike Mooney is one of the foremost experts on tunnels who brings expansive expertise to the position, both in research and in practical applications internationally.”